Cranckcase conditioning oil



Patented Sept. 6, 1949 CRANCKCASE CONDITIONING OIL C. Newbold Watson, Wynnewood, Pa., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application April 5, 1947, Serial No. 739,658

1 Claim. 1

This invention relates to a crankcase conditioning oil and more particularly to a crankcase flushing and lubricating oil of the type employed for temporarily lubricating and cleansing the motors of automotive vehicles and internal combustion engines of comparable type.

It has been suggested in the prior art that certain cleansing compositions consisting partly or largely of suitable mineral oil base materials be used either in admixture with regular lubricating oil or by themselves for the purpose of cleansing the crankcase, cylinder walls, pistons, and other parts of carbonaceous, resinous, asphaltic, tarry and sludge deposits of various types and sources. It is desirable that such cleansing be accomplished during normal operation, and that the cleansing agent be also a lubricant during the period of cleansing.

The value of frequent engine cleansing is widely recognized, such cleansing being of particular utility in preventing clogging of oil systems, facilitating adequate lubrication and thereby preventing excessive wear, freeing frozen or stuck parts, such as valves, piston rings, and the like, and otherwise substantially improving the performance of internal combustion engines. The compositions used in the past, however, have not always been satisfactory, being deficient either in their cleansing capacity or their lubrieating efficiency, or being corrosive in character, or being otherwise objectionable in many cases.

It is an object of my invention to supply an improved flushing composition which will be substantially free of the above-mentioned objections and to accomplish the foregoing by the use of readily available materials which are not excessive in cost and which can be used in a simple and efiicient manner to cleanse internal combustion engines effectively without requiring disassembly and reassembly operations.

I have found that by using a composition comprising from to 25% of an oil soluble metalloorganic base such as a metal petroleum sulfonate, or naphthenate mixed with from 25% to 40% of an aromatic solvent naphtha and from 40% to 50% of an aromatic extract obtained by solvent treatment of certain residual mineral oils, a very satisfactory conditioning oil may be obtained. Such a mixture as just described may be added to regular crankcase motor oil in proportions of 10% to 50% and used in the crankcase in the same way as regular lubricant. Preferably, such a mixture is used in lieu of, or in combination with a normal lubricating oil, for a suitable period, long enough to dissolve objectionable foreign matter which accumulates on engine parts, and then is drained so that the regularlubricant may be replaced. Commonly a composition of this character mixed with lubricating oil will be used in automotive vehicles for about 50 to 500 miles depending upon the character of the vehicles and the amount and character of objectionable deposits.

As a specific example, a mixture of 11% by weight of sodium petroleum sulfonates, 1% of diethylene glycol, 3% of sodium naphthenates, 35% of an aromatic solvent naphtha having a boiling range of about 300 to 370 F., 5% of an extracted Coastal mineral oil seconds viscosity at 210 F.) and 45% of an aromatic extract obtained by solvent treatment of residual lubricating stocks, was tested and found to be a very satisfactory composition. The solvent extract was prepared by phenol extraction of 2. Coastal naphthenic oil having a viscosity of about 500 S. S. U. at 100 F. Solvent naphtha was aromatic and had a kauri-butanol value of 80.

The product just described was found to have the following physical characteristics:

Gravity, API 17.0 Flash, F. (Closed cup) 115 Viscosity SSU at F 70.6 Carbon residue, per cent 4.20 Ash, per cent 1.81

This material was added in a quantity of approximately 20% of the crankcase motor oil capacity together with 80% of regular lubricating oil. The engine was allowed to operate in normal service from 300 to 500 miles and thereafter the crankcase was drained and regular motor oil reinstalled.

In a further and more extensive test involving use of a large number of trucks in commercial service and operating under various conditions, the product described above was found to be very efiective in desludging automotive engines where the sludge was of the cold engine type. It is not as effective in removing high temperature varnish type sludge, although it has some utility for this purpose. Cold engine sludges, however, are a major problem, involving about 80% of sludge troubles in engines of the automotive type.

In a competitive test conducted on a fleet of dairy trucks, half of the trucks were treated with a well refined lubricating oil containing 20% of the above product and the other half were lubricated with a commercial heavy duty lubricating oil containing a detergent used in the prior art. After 5 months operation on these products, all the engines were dismantled and examined.

3 Those operating on the heavy duty detergent oil were found to be very badly sludged, whereas those operating on the lubricating oil with of my improved flushing oil incorporated therein were found to be exceptionally clean.

In another test, aChevrolet taxicab fleet which had encountered severe engine sludging and particularly clogging of the rocker arm system, was lubricated with a 20% solution in standard lubric'ating oil of my improved flushing oil. Further sludging and oil system clogging. were entirely eliminated in a test running over a period of a number of months.

Still another test was conducted to determine damage which might result from corrosion of bearings or clogging of oil screens or 01F passages on the removal of sludge deposits. A lid-hour high temperature test on a standard Chevrolet engine was carried out according to the procedure described in U. S. Army specification 2-104B for the evaluation of heavy duty oils. The motor was operated for 36 hours continuously at a speed equivalent to 60 miles per hour and at an oil temperature maintained at 280 F.

In this test my improved flushing oil was used H in 30% concentration in standard lubricating oil. Bearing corrosion was found to be no greater than in the case of standard lubricating oil and engine cleanliness and mechanical conditions were found to be superior. w

The improved performance of the flushing oil in comparison with competitive flushing, solvents or compounds appears to be due to a combination of very effective solvency with the emulsifying and dispersing properties of a Water-sensitive d'etergent soap. Solvents for carbonaceous products of fuels and oil decomposition in engine crankcases have been known in the prior art. However, when such deposits are in the form of an emulsion of water with lubricating. oil, organic solvents have proved in the past t be relatively ineffective. This is due, apparently, to the protective action of the Water emulsion. By combining effective solvency with an emulsifying dispersant the protective action of the emulsion component of the sludge appears to be overcome. The solvent naphtha serves to remove deposits from parts not normally contacted with effective amounts of an ordinary flushing oil the naphtha.- tending to distill into the. upper parts of an internal combustion engine in an automotive vehicle, for example. The solvent extract remains in the crankcase to serve as a solvent there:

As another example, a composition containing. by weight of an oil soluble metal sulfonate, specifically calcium sulfonate, mixed with: 25%- of aromatic solvent naphtha and- 50% or aromatic extract obtained by the: solvent treatment of na-phthenic distillate, was found to be-substan tially equally satisfactory. My experiments in! dicate that various oil soluble sulforratessuchaas those of calcium, barium. sodium and the. like; as well as naphthenates of these and related mete als', may be used successfully. In general, they will compose from 10 to 25%; by weight of the flushing oil, although lesser or greater quantities may be used if desired. The aromatic solvent naphtha may have a boiling range" between 250 and 450 F. and may be used in percentages" ranging from 20 to 50% or moreof the total Chm-f position. The other component; as suggested above, is preferably an aromatic extract obtained by conventional solvent treatment either of naphthenic distillate or residual" lubricating stock's.- Mixtures of extracts from these sources may be used satisfactorily in any proportions, such materials comprising at least 25% and preferably making up 45 to of the flushing or tio n l composition. Here again these limits are not critical, greater or lesser quantities being useful, but the ranges preferred are as indimted.

Flushing or conditioning oils prepared as above may be used without dilution and the are particularly efiective cleansing agents when mildly heatedl- Preferably, however, they are used in standard lubricating oils over substantial periods ofl time permitting the solvent constituents sumcient time tov loosen and dissolve the undesirable deposits in crankcases, valve compartments; piston ring grooves, and the like. Ordiiiari'ly' they will be used in proportions of 10% to 50% or crankcase capacity in connection with lubricating oils of the type and grade approved for the particular engines being treated.

As will be obvious. to those skilled in the" art, various modifications maybe made in the composition and other additives, such as corrosion inhibitors antioxidants, extreme pressure agents, and the like, may be used in or in conjunction with. flushing. oils with or without lubricating oil dilution.

As suggested above, oil soluble metal naphthenates may be used to replace the oil soluble metal sulfonates Wholly or inpart. Thus a very satisfactory compositionv may include both sodium sulfonate and sodium na'phthenat'e. For exa-m-ple, instead of using 10 to 25% sodium sul fonate, the composition may contain 0 to 25% sodium sulfbnate and 25 to 0% of sodium naphthenate. A preferred range is from 3' to 15% sodium sul'fonate and 2 to I0 percent sodium naphthenate. In lieu of. either or both, the corresponding. calcium salts may be used in likeproportions The total preferably amounts to at least. about 10 based on the weight of the whole composition.

It is also desirable to include a small amount or a. polyhydricalcohol, for example Oll to 5.0% oil a glycol. suchas diethylene glycol. Ingredients of this character enhance the cleaning characteristics of! the crankcase conditioning oil and con-tribute in some measure to its lubricating values. The solventsemployed are as described above, and. the composition so prepared is-prefera'bly used as an additive to a regular crankcase lubricating. oil. in proportions of 10' to 50%, based onthe total finished lubricant, as previously described. I

As a further specific example, a composition was. prepared having the followin composition:

The solvent consisted of about 40% aromatic solvent naphtha and about 60% aromatic ex"- gist; by" solvent: extraction, of residual mineral The composition just described may be added to conventional crankcase lubricatin oils in vari'-- ous proportions as previousl described, about 20% being, considered a preferable proportion.

I claim:

A. lubricating com osition havin cleansing roperties consisting essentially" of mineral base lubricating oiror internal combustion crankcase 6 lubricating grade, containing about of 9. REFERENCES CITED composition of the following approximate proportions by weight: The following references are of record in the Percent file Of this patent:

Oil soluble sodium petroleum sulfonate 11 5 UNITED STATES PATENTS Sodium naphthen-ate 3 Diethylene glycol 1 Number Name a Aromatic solvent naphtha of boiling range 2,340,035 zlmmel' 1944 about 300 to 370 F 3,3 2 232 E ag Nov}; 1i:S 134(1J Mineral 011 of about so s. s. U. viscosit at 1 Sep 1 ,1 4

2 F i 5 10 2,355,591 Flaxman Aug. 8, 1944 Phenol extract; of Coastal naphthenlc 011 of 2415353 Johnston 4, 194'7 about 500 S. S. U. viscosity at 100 F C. NEWBOLD WATSON. 15 

